This invention relates generally to wireline communications systems and is particularly directed to a dual mode telephone capable of operating in either a standard telephone network or via the Internet.
The cost per minute of Internet access is approaching, and may soon be less than, the cost per minute of long distance telephone service. As a result, increasing numbers of telecommunications users are using voice over the Internet to place toll calls rather than via a standard telephone network. The Internet provides acceptable voice quality at a cost much less than that of a traditional long distance call.
Using the Internet to make a phone call currently requires the user to initiate the call using a personal computer (PC) in combination with a modem to contact an Internet Service Provider (ISP). After initially contacting the ISP, the user must then go through a complex log-on process to gain access to the Internet. Once logged on, the user must then employ an Internet telephony software package in entering the number to be called. The network of the ISP then connects the user to the called party via the Internet. Many potential Internet telephony users find the complexity of this procedure unacceptable and refuse to use the Internet in this communications context in favor of the more familiar, traditional long distance telephone service. In addition, even after the user goes through the complex procedure to establish an Internet telecommunications link, communication via the Internet is not entirely reliable may not be possible for any of several reasons. For example, all ISP ports may be busy or there may be insufficient connection bandwidth available to the desired destination.
There are also available single mode, digital phones having access to the Internet via a Local Area Network (LAN). This is also not a particularly reliable communications link because of the limited availability of the LAN which is typically shared by a large number of users.
The present invention addresses the aforementioned limitations of the prior art by providing a dual mode Internet telephone have a selectable mode switch which is capable of communicating either via a standard toll telephone network or via the Internet and which automatically reverts to the standard toll telephone network operation when Internet telephony is not available.
This invention contemplates a dual mode Internet telephone with a mode control switch either of the manual type or which is processor controlled. The operation of the dual mode telephone is conceptually similar to current tone/pulse dialed telephones, where the user is able to control whether dial pulses or Dual Tone Multi-Frequency (DTMF) tones are sent in response to dialing. The inventive dual mode phone includes a Standard/Internet Mode Switch that allows the user to choose between making the call over a standard telephone network or via the Internet. A programmed processor may also be used to automatically control the mode of the switch. In the standard mode of operation, most of the advanced Internet telephony circuitry in the phone is disabled, and the dial/touchtone keypad, earpiece and mouthpiece, and ringer are connected to the metallic telephone line as in a standard telephone network. In the Internet mode of operation, when the user goes off hook, a connection is automatically established to a pre-programmed Internet Service Provider (ISP) number(s). The dialed digits are stored and converted to Internet telephony call set-up messages. The signals to/from the earpiece and mouthpiece are digitized, compressed and packetized by a digital signal processor. A built-in modem connects the digital signal processor and the call controlled messages through the standard telephone line to the ISP. A control processor manages the connections, and drives the keypad and ringer. A nonvolatile memory stores configuration data such as the ISP number(s) to call, and various Internet mode control information. The mode control switch may be automatically controlled by logic within the control processor which takes into consideration such information as the dialed digits, time of day, and other factors to determine if it is most advantageous to complete the call over the Internet or via the standard telephone network. Provision is made for the user to override the automatic selection of mode of communication. The dual mode Internet telephone can receive calls via the standard telephone network or the Internet. If the ISP is attempting to complete a connection to a subscriber with the inventive dual-mode telephone, the ISP calls the user""s directory number and, based on detecting the caller ID of the ISP, the dual mode Internet telephone configures itself to an Internet mode, picks up the line and establishes a connection. The user then receives a distinctive ring and has the option to pick up the receiver and answer the call.